Novel Membrane Emulsification Method of Producing Highly Uniform Silica Particles Using Inexpensive Silica Sources

A membrane emulsification method for production of monodispersed silica-based ion exchange particles through water-in-oil emulsion route is developed. A hydrophobic microsieve membrane with 15 mu m pore size and 200 pm pore spacing was used to produce droplets, with a mean size between 65 and 240 pm containing acidified sodium silicate solution (with 4 and 6 wt% SiO2) in kerosene. After drying, the final silica particles had a mean size in the range between 30 and 70 mu m. Coefficient of variation for both the droplets and particles did not exceed 35%. The most uniform particles had a mean diameter of 40 mu m and coefficient of variation of 17%. The particles were functionalised with 3-aminopropyltrimethoxysilane and used for chemisorption of Cu(II) from an aqueous solution of CuSO4 in a continuous flow stirred cell with slotted pore microfiltration membrane. Functionalised silica particles showed a higher binding affinity toward Cu(II) than nontreated silica particles.UK Colloids 2011 - International Colloid and Surface Science Symposium, Jul 04-06, 2011, London, Englan